Provide Struct data type support for oracle plugin

database-commons/src/main/java/io/cdap/plugin/db/CommonSchemaReader.java

@@ -57,6 +57,11 @@ public Schema getSchema(ResultSetMetaData metadata, int index) throws SQLExcepti
                              metadata.isSigned(index), true);
   }
 
+  public Schema getSchema(String typeName, int sqlType, int precision, int scale, String columnName,
+                          boolean isSigned) throws SQLException {
+    return DBUtils.getSchema(typeName, sqlType, precision, scale, columnName, isSigned, true);
+  }
+
   @Override
   public boolean shouldIgnoreColumn(ResultSetMetaData metadata, int index) throws SQLException {
     return false;

database-commons/src/main/java/io/cdap/plugin/db/DBRecord.java

@@ -188,6 +188,11 @@ protected void handleField(ResultSet resultSet, StructuredRecord.Builder recordB
   protected void setField(ResultSet resultSet, StructuredRecord.Builder recordBuilder, Schema.Field field,
                           int columnIndex, int sqlType, int sqlPrecision, int sqlScale) throws SQLException {
     Object o = DBUtils.transformValue(sqlType, sqlPrecision, sqlScale, resultSet, columnIndex);
+    setFieldValue(recordBuilder, field, o);
+  }
+
+  protected void setFieldValue(StructuredRecord.Builder recordBuilder, Schema.Field field, Object o)
+          throws SQLException {
     if (o instanceof Date) {
       recordBuilder.setDate(field.getName(), ((Date) o).toLocalDate());
     } else if (o instanceof Time) {

oracle-plugin/src/main/java/io/cdap/plugin/oracle/OracleSourceDBRecord.java

@@ -29,12 +29,17 @@
 import java.io.InputStream;
 import java.lang.reflect.InvocationTargetException;
 import java.math.BigDecimal;
+import java.math.RoundingMode;
 import java.nio.ByteBuffer;
+import java.sql.Blob;
+import java.sql.Clob;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
+import java.sql.SQLXML;
+import java.sql.Struct;
 import java.sql.Timestamp;
 import java.sql.Types;
 import java.time.LocalDateTime;
@@ -43,6 +48,8 @@
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
 
 /**
  * Oracle Source implementation {@link org.apache.hadoop.mapreduce.lib.db.DBWritable} and
@@ -106,13 +113,90 @@ record = recordBuilder.build();
   @Override
   protected void handleField(ResultSet resultSet, StructuredRecord.Builder recordBuilder, Schema.Field field,
                              int columnIndex, int sqlType, int sqlPrecision, int sqlScale) throws SQLException {
-    if (OracleSourceSchemaReader.ORACLE_TYPES.contains(sqlType) || sqlType == Types.NCLOB) {
+    if (OracleSourceSchemaReader.ORACLE_TYPES.contains(sqlType) || sqlType == Types.NCLOB || sqlType == Types.STRUCT) {
       handleOracleSpecificType(resultSet, recordBuilder, field, columnIndex, sqlType, sqlPrecision, sqlScale);
     } else {
       setField(resultSet, recordBuilder, field, columnIndex, sqlType, sqlPrecision, sqlScale);
     }
   }
 
+  @Override
+  protected void setFieldValue(StructuredRecord.Builder recordBuilder, Schema.Field field, Object attrValue)
+          throws SQLException {
+    if (attrValue == null) {
+      recordBuilder.set(field.getName(), null);
+      return;
+    }
+
+    Schema fieldSchema = field.getSchema().isNullable() ? field.getSchema().getNonNullable()
+            : field.getSchema();
+    String attrClassName = attrValue.getClass().getName();
+    if (attrValue instanceof Struct) {
+      recordBuilder.set(field.getName(), convertStructToRecord((Struct) attrValue, fieldSchema));
+      return;
+    }
+    if (attrValue instanceof Clob) {
+      Clob clob = (Clob) attrValue;
+      recordBuilder.set(field.getName(), clob.getSubString(1, (int) clob.length()));
+      return;
+    }
+    if (attrValue instanceof Blob) {
+      Blob blob = (Blob) attrValue;
+      recordBuilder.set(field.getName(), blob.getBytes(1, (int) blob.length()));
+      return;
+    }
+    if (attrValue instanceof SQLXML) {
+      recordBuilder.set(field.getName(), ((SQLXML) attrValue).getString());
+      return;
+    }
+    if ("oracle.sql.INTERVALDS".equals(attrClassName) || "oracle.sql.INTERVALYM".equals(attrClassName)) {
+      recordBuilder.set(field.getName(), attrValue.toString());
+      return;
+    }
+    if (attrValue instanceof BigDecimal) {
+      populateDecimalValue((BigDecimal) attrValue, fieldSchema, recordBuilder, field);
+      return;
+    }
+
+    if (attrValue instanceof Timestamp) {
+      Timestamp timestamp = (Timestamp) attrValue;
+      if (Schema.LogicalType.DATETIME.equals(fieldSchema.getLogicalType())) {
+        recordBuilder.setDateTime(field.getName(), timestamp.toLocalDateTime());
+      } else {
+        super.setFieldValue(recordBuilder, field, attrValue);
+      }
+      return;
+    }
+    if (attrValue instanceof OffsetDateTime) {
+      ZonedDateTime zonedDateTime = ((OffsetDateTime) attrValue).atZoneSameInstant(ZoneId.of("UTC"));
+
+      if (fieldSchema.getLogicalType() != null &&
+              (Schema.LogicalType.TIMESTAMP_MICROS.equals(fieldSchema.getLogicalType()) ||
+                      Schema.LogicalType.TIMESTAMP_MILLIS.equals(fieldSchema.getLogicalType()))) {
+        recordBuilder.setTimestamp(field.getName(), zonedDateTime);
+      } else if (Schema.LogicalType.DATETIME.equals(fieldSchema.getLogicalType())) {
+        Timestamp timestampLTZ = Timestamp.from(zonedDateTime.toInstant());
+        recordBuilder.setDateTime(field.getName(),
+                OffsetDateTime.of(timestampLTZ.toLocalDateTime(),
+                        ZonedDateTime.now().getOffset()).toLocalDateTime());
+      } else {
+        recordBuilder.set(field.getName(), zonedDateTime.toString());
+      }
+      return;
+    }
+
+    ClassLoader oracleLoader = attrValue.getClass().getClassLoader();
+      try {
+          if (oracleLoader != null && oracleLoader.loadClass("oracle.jdbc.OracleBfile").isInstance(attrValue)) {
+            recordBuilder.set(field.getName(), getBfileBytes(attrValue, field.getName()));
+            return;
+          }
+      } catch (ClassNotFoundException e) {
+          throw new RuntimeException(e);
+      }
+      super.setFieldValue(recordBuilder, field, attrValue);
+  }
+
   @Override
   protected void writeNonNullToDB(PreparedStatement stmt, Schema fieldSchema,
                                   String fieldName, int fieldIndex) throws SQLException {
@@ -169,6 +253,33 @@ protected void writeNonNullToDB(PreparedStatement stmt, Schema fieldSchema,
     }
   }
 
+  private void populateDecimalValue(BigDecimal bigDecimal, Schema fieldSchema,
+      StructuredRecord.Builder recordBuilder, Schema.Field field) {
+    if (Schema.LogicalType.DECIMAL.equals(fieldSchema.getLogicalType())) {
+      recordBuilder.setDecimal(field.getName(), bigDecimal.setScale(fieldSchema.getScale(), RoundingMode.HALF_UP));
+      return;
+    }
+    switch (fieldSchema.getType()) {
+      case DOUBLE:
+        recordBuilder.set(field.getName(), bigDecimal.doubleValue());
+        break;
+      case FLOAT:
+        recordBuilder.set(field.getName(), bigDecimal.floatValue());
+        break;
+      case INT:
+        recordBuilder.set(field.getName(), bigDecimal.intValue());
+        break;
+      case LONG:
+        recordBuilder.set(field.getName(), bigDecimal.longValue());
+        break;
+      case STRING:
+        recordBuilder.set(field.getName(), bigDecimal.toPlainString());
+        break;
+      default:
+        recordBuilder.set(field.getName(), bigDecimal);
+    }
+  }
+
   /**
    * Creates an instance of 'oracle.sql.TIMESTAMPTZ' which corresponds to the specified timestamp with time zone string.
    * @param connection sql connection.
@@ -232,11 +343,15 @@ private Object createOracleTimestamp(Connection connection, String timestampStri
    */
   private byte[] getBfileBytes(ResultSet resultSet, String columnName) throws SQLException {
     Object bfile = resultSet.getObject(columnName);
+    return getBfileBytes(bfile, columnName);
+  }
+
+  public byte[] getBfileBytes(Object bfile, String columnName) {
     if (bfile == null) {
       return null;
     }
     try {
-      ClassLoader classLoader = resultSet.getClass().getClassLoader();
+      ClassLoader classLoader = bfile.getClass().getClassLoader();
       Class<?> oracleBfileClass = classLoader.loadClass("oracle.jdbc.OracleBfile");
       boolean isFileExist = (boolean) oracleBfileClass.getMethod("fileExists").invoke(bfile);
       if (!isFileExist) {
@@ -341,6 +456,14 @@ private void handleOracleSpecificType(ResultSet resultSet, StructuredRecord.Buil
       case OracleSourceSchemaReader.LONG_RAW:
         recordBuilder.set(field.getName(), resultSet.getBytes(columnIndex));
         break;
+      case Types.STRUCT:
+        Struct structValue = (Struct) resultSet.getObject(columnIndex);
+        if (structValue != null) {
+          recordBuilder.set(field.getName(), convertStructToRecord(structValue, nonNullSchema));
+        } else {
+          recordBuilder.set(field.getName(), null);
+        }
+        break;
       case Types.DECIMAL:
       case Types.NUMERIC:
         // This is the only way to differentiate FLOAT/REAL columns from other numeric columns, that based on NUMBER.
@@ -371,6 +494,54 @@ private void handleOracleSpecificType(ResultSet resultSet, StructuredRecord.Buil
     }
   }
 
+  /**
+   * Converts a JDBC {@link Struct} into a {@link StructuredRecord} based on the provided schema.
+   *
+   * @param struct the SQL structured type containing the source data attributes
+   * @param schema the target record schema defining the fields to map
+   * @return a populated {@code StructuredRecord} instance
+   * @throws SQLException if an error occurs reading the struct attributes or metadata
+   */
+  protected StructuredRecord convertStructToRecord(Struct struct, Schema schema)
+      throws SQLException {
+    Map<String, Object> attributeMap = getAttributeMap(struct, schema);
+    StructuredRecord.Builder builder = StructuredRecord.builder(schema);
+
+    for (Schema.Field field : schema.getFields()) {
+      Object attrValue = attributeMap.get(field.getName());
+      setFieldValue(builder, field, attrValue);
+    }
+    return builder.build();
+  }
+
+  /**
+   * Extracts attributes from a {@link Struct} into a case-insensitive map indexed by column name.
+   * Uses reflection to extract underlying metadata (e.g., from Oracle StructDescriptor).
+   *
+   * @param struct the source SQL structured type
+   * @param schema the target schema used for context in error messages
+   * @return a case-insensitive {@code Map} linking column names to their attribute values
+   * @throws SQLException if metadata extraction fails or driver-specific methods are inaccessible
+   */
+  private Map<String, Object> getAttributeMap(Struct struct, Schema schema) throws SQLException {
+    Map<String, Object> attributeMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+    Object[] attributes = struct.getAttributes();
+    if (attributes != null) {
+      try {
+        Object descriptor = struct.getClass().getMethod("getDescriptor").invoke(struct);
+        ResultSetMetaData metaData =
+                (ResultSetMetaData) descriptor.getClass().getMethod("getMetaData").invoke(descriptor);
+        for (int i = 1; i <= metaData.getColumnCount() && (i - 1) < attributes.length; i++) {
+          attributeMap.put(metaData.getColumnName(i), attributes[i - 1]);
+        }
+      } catch (Exception e) {
+        throw new SQLException(String.format("Failed to retrieve attribute metadata for Oracle STRUCT schema '%s': %s",
+                schema.getRecordName(), e.getMessage()));
+      }
+    }
+    return attributeMap;
+  }
+
   /**
    * Get the scale set in Non-nullable schema associated with the schema
    * */